Stripping in construction most commonly refers to removing the temporary molds, called formwork, that hold poured concrete in place while it hardens. Once the concrete reaches sufficient strength, workers carefully detach and remove these wooden, steel, or plastic forms to reveal the finished structure underneath. The term also applies to a separate process in building maintenance: chemically removing old floor finish so a new coat can be applied. Both meanings come up regularly on job sites, though formwork stripping is the more frequent use in construction work.
How Concrete Formwork Stripping Works
When concrete is poured for walls, columns, slabs, or beams, it flows into pre-built molds that give it shape. These molds, or forms, stay in place until the concrete cures enough to support itself. Stripping is the process of breaking those forms free and removing them piece by piece.
The basic sequence starts with unfastening any bolts, screws, or nails holding the formwork together. Workers then use pry bars or flat bars to gently loosen form boards from the hardened concrete surface. A claw hammer handles nail removal and light tapping, while duplex nail pullers speed up the removal of double-headed nails that were designed for easy extraction. If metal stakes were driven into the ground to brace the forms, a stake puller makes removal far easier on the body. Reusable forms made from steel or plastic often have built-in release mechanisms that simplify the process.
The goal is to separate the formwork without damaging the concrete underneath. Prying too aggressively can chip edges or crack surfaces that haven’t fully cured, so the work moves slowly and deliberately.
When Forms Can Be Removed
Timing is the critical decision in stripping, and it depends on what the formwork is supporting. Forms for vertical surfaces like columns and walls, which don’t bear the weight of the concrete above them, can typically be removed after 12 hours as long as the concrete has hardened enough to resist damage during the process. Forms and shoring that support the actual weight of concrete, such as those under slabs and beams, must stay in place much longer. A common minimum is four days, though the real requirement is that the concrete reaches a specified strength before any load-bearing support is taken away.
Temperature plays a significant role in this timeline. Hot weather accelerates concrete hardening, sometimes reducing the plastic (workable) stage to an hour or less. Cold weather does the opposite, slowing the chemical reaction that gives concrete its strength and potentially extending the time before stripping is safe. Project engineers typically test concrete strength using sample cylinders rather than relying on time alone, especially for structural elements where premature removal could cause a collapse.
Why Stripping Is Considered High-Risk
Formwork stripping is one of the most dangerous operations in concrete work. The central risk is removing forms before the concrete can support itself, which can lead to partial or full structural failure. Workers are also exposed to falling debris, unstable partially stripped structures, and slip-and-trip hazards from loose materials on the ground.
Several safety rules govern the process. Workers should never strip forms without first verifying that the concrete has reached sufficient strength. Bracing must be confirmed as adequate before any formwork is broken free. Only as much formwork should be stripped as can be cleaned up during the same shift, preventing hazardous clutter from accumulating. Climbing on partially stripped formwork to reach higher areas is prohibited; work platforms are required instead. Stripped material should never be thrown to the ground from height. It gets passed down to a co-worker or lowered by other controlled methods. After stripping, the area is inspected for loose concrete or debris that could cause injuries.
Floor Stripping in Construction and Maintenance
The other common use of “stripping” on construction and maintenance sites refers to removing old floor finish. Over time, layers of floor coating build up, yellow, or stop responding to regular cleaning and buffing. When that happens, the old finish is chemically dissolved and scraped away so a fresh coating can be applied.
The process starts with dry dust-mopping to clear loose debris, then scraping off any gum or stuck-on material. Painters tape protects baseboards and surfaces that shouldn’t contact the chemical stripper. A stripping solution is diluted with cold water at ratios that depend on the floor type and how many coats of old finish need to come off. A stronger concentration (1 part stripper to 8 parts water) is used for first-time strip jobs on vinyl composite tile, terrazzo, or concrete, or when more than 10 coats of finish have built up. A weaker mix (1 to 16) works for specialty surfaces like luxury vinyl tile, linoleum, or rubber flooring, and for floors with fewer layers of old finish.
The diluted stripper is mopped onto the floor, starting with the perimeter. An edge tool or floor scraper handles baseboards and corners. A rotary machine fitted with an abrasive pad then scrubs the main floor area, breaking the old finish into a slurry. That slurry is vacuumed up with a wet vac. Alternatively, an auto scrubber can handle the job in multiple passes: one to scrub with the squeegee raised, a second to pick up the slurry, and a third rinse pass with clean water. Once the floor is clean and dry, new finish coats are applied.
Safety Concerns With Floor Stripping
Wet, chemically treated floors create significant slip hazards, so anti-slip footwear and wet floor signage are standard. The repetitive motion of scrubbing and operating heavy floor machines can cause overexertion and strain injuries, making task rotation important. Chemical exposure is a concern since stripping solutions are caustic, and any electrically powered equipment used on a wet surface needs a ground fault circuit interrupter to prevent electrocution. Workers inspect power cords for fraying before starting and avoid flooding the floor with excess solution.